Commit 32c7f202 authored Aug 08, 2011 by Wu Fengguang

btrfs: fix dirtied pages accounting on sub-page writes



When doing 1KB sequential writes to the same page,
balance_dirty_pages_ratelimited_nr() should be called once instead of 4
times, the latter makes the dirtier tasks be throttled much too heavy.

Fix it with proper de-accounting on clear_page_dirty_for_io().

CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

parent 2f800fbd

fs/btrfs/file.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1136,7 +1136,8 @@ again:
		GFP_NOFS);
		}
		for (i = 0; i < num_pages; i++) {
		clear_page_dirty_for_io(pages[i]);
		if (clear_page_dirty_for_io(pages[i]))
		account_page_redirty(pages[i]);
		set_page_extent_mapped(pages[i]);
		WARN_ON(!PageLocked(pages[i]));
		}